Androstenedione

Definition

Androstenedione is a steroid hormone that is an intermediate in the biosynthesis of the male sex hormone testosterone. It is produced primarily in the gonads and adrenal glands and plays a role in regulating sexual development and function.

5 Must Know Facts For Your Next Test

1. Androstenedione is a precursor to testosterone, meaning it can be converted into testosterone in the body.
2. In women, androstenedione is produced in the ovaries and adrenal glands, while in men, it is primarily produced in the testes.
3. Elevated levels of androstenedione can lead to increased production of testosterone, which can result in virilization (development of male characteristics) in women.
4. Androstenedione is often used as a performance-enhancing supplement, but its use is banned in many sports due to its potential for abuse and side effects.
5. Measurement of androstenedione levels can be used to help diagnose certain hormonal disorders, such as congenital adrenal hyperplasia.

Review Questions

• Explain the role of androstenedione in the biosynthesis of testosterone.
  • Androstenedione is a key intermediate in the biosynthesis of testosterone. The enzyme 17β-hydroxysteroid dehydrogenase catalyzes the conversion of androstenedione to testosterone. This conversion occurs primarily in the testes in men and the ovaries and adrenal glands in women. The availability of androstenedione, along with the activity of this enzyme, is a critical factor in regulating the production of testosterone, which is essential for the development and maintenance of male sexual characteristics.
• Describe the potential consequences of elevated androstenedione levels in women.
  • Elevated levels of androstenedione in women can lead to increased production of testosterone, a process known as virilization. This can result in the development of masculine physical characteristics, such as increased facial and body hair, deepening of the voice, and enlargement of the clitoris. Prolonged exposure to high androstenedione levels can also disrupt the normal menstrual cycle and contribute to the development of polycystic ovary syndrome (PCOS), a condition characterized by irregular periods, infertility, and metabolic abnormalities.
• Analyze the role of androstenedione measurement in the diagnosis of hormonal disorders.
  • Measuring androstenedione levels can be a valuable tool in the diagnosis of certain hormonal disorders, such as congenital adrenal hyperplasia (CAH). In CAH, a genetic defect in one of the enzymes involved in cortisol biosynthesis leads to an accumulation of androstenedione and other androgenic precursors. Elevated androstenedione levels, along with other clinical and laboratory findings, can help healthcare providers diagnose CAH and guide appropriate treatment. Additionally, androstenedione measurements can be used to monitor the effectiveness of treatment in individuals with hormonal imbalances, as well as to screen for potential doping in competitive sports where the use of performance-enhancing substances is banned.

Related terms

Testosterone:

A male sex hormone that is responsible for the development of male sexual characteristics and plays a role in regulating sexual function, muscle mass, and bone density.

Adrenal Glands:

Endocrine glands that sit atop the kidneys and produce hormones such as cortisol, aldosterone, and androstenedione.

Steroid Hormones:

A class of lipid-soluble hormones derived from cholesterol that include sex hormones, corticosteroids, and others, and play crucial roles in various physiological processes.